cDNA cloning and analysis of tissue-specific gene expression of rat urocortin II

摘要

The corticotropin-releasing hormone (CRH) family of neuropeptides includes CRH (a 41-amino acid hypothalamic peptide) and urocortin. Corticotropin-releasing factor (CRF), a peptide first isolated from mammalian, plays an important role in the regulation of the pituitary-adrenal axis, and in endocrine, autonomic, immune and behavioral responses to stress. In this study, we cloned rat urocortin II (UCN II) cDNA from rat mid-brain by RT-PCR. The rat UCN II clone contained an open reading frame (ORF) 109 amino acids which shared 90% and 63% homology with mouse and human homologues, respectively. The expression of UCN II mRNA is mainly distributed in bone marrow, ovary, uterus, hypophysis, adrenal gland, and skin. In this study, rat recombinant UCN was expressed in E. coli and purified in active form. Furthermore, purified recombinant UCN II protein specifically binds to CRF receptor 2 in rat ROS 17 / 2.8 and GH3 cells by flow-cytometry analysis. UCN II cDNA clone obtained in this study will be useful for further investigation on behavioral responses to stress in rats. [PUBLICATION ABSTRACT]